A trust look-up protocol is described that allows a meta-trusted third party, or trust directory, to mediate between parties of potential business collaborations and trusted third parties that are counted on to authorize or otherwise validate the business collaborations. The trust directory receives a trust request for a collaboration from one or more parties, and, based on the request, determines a specialty of a trusted third party that is suited to the request and the collaboration. The trust directory then obtains interface information for the trusted third party for forwarding to the requesting party. In this way, the trusted third party may make a determination as to whether the requesting party should proceed in the business collaboration. Afterwards, the trust directory may monitor communications that take place as part of the collaboration, for use in evaluating future requests and collaborations.